The role of calcium in the control of renin release.
The effects of removing external calcium and inhibiting entry of calcium into the cell by treatment with D-600 on renin release from renal cortical slices of male Sprague-Dawley rats were examined. Baseline renin release, angiotensin II (AII)-induced inhibition, and isoproterenol-induced stimulation of renin release were studied. Removal of external calcium by chelation with 5 mM EGTA inhibited basal renin release while treatment with 1 mM EGTA stimulated basal renin release slightly. Incubation of slices with zero calcium medium containing 1 mM EGTA had no effect on isoproterenol-induced stimulation of renin release. In contrast, similar treatment reduced the inhibitory effect of AII from 58.7% of baseline to 85.3% (p less than 0.001). Similarly, blockage of calcium entry into cells with D-600 had no effect on isoproterenol-induced stimulation of renin release but abolished AII-induced inhibition. Replacement of sodium in the bathing medium with choline had no effect on baseline renin release or on AII-induced inhibition of renin release, ruling out the possibility that D-600 altered renin release via an effect on sodium influx. Taken together, the data strongly suggest that AII-induced inhibition of renin release is partially dependent on the presence of external calcium but that isoproterenol-induced stimulation of renin release is not.
D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000502:physiology*; D002463:Cell Membrane Permeability; D004533:Egtazic Acid / Q000494:pharmacology; D005711:Gallopamil / Q000494:pharmacology; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D007668:Kidney / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012083:Renin / Q000378:metabolism*; D012964:Sodium / Q000502:physiology
D000804:Angiotensin II; D005711:Gallopamil; D004533:Egtazic Acid; D012964:Sodium; D012083:Renin; D007545:Isoproterenol; D002118:Calcium